This, as well as the Secure Boot option to be enabled.
These insanely high hardware requirements are the hottest topic these days in the Windows community. Even though Microsoft has done its best to communicate, a lot of users are still confused whether they will be able to get the new OS via Windows Update after launch.
And then you have situations like this that add to the confusion.
As the screenshot above shows, the game will not start on unsupported Windows 11 PCs that did not have the necessary hardware for Trusted Platform Module 2.0 and Secure Boot. The message made clear that in order to play, users had to have these two technologies built into their systems.
Apparently, this rule is being enforced on Windows 11, but the game continues to be playable on Windows 10 PCs without these issues.
This, in fact, led to Microsoft clarifying that the error message had nothing to do with the Windows 11 preview build. In other words, what is happening is coming from Riot Games themselves.
Speaking of, the game developer recently updated its Vanguard anti-cheat system to enforce TPM 2.0 and Secure Boot, and this powerful software is packaged with the game to keep an eye on processes running in the background whether the game is being played or not.
Hopefully, the company sheds a little light on this soon.